This is a great video for beginners of SEO and actually does touch on a
number of important points but there is still a few things that you should
point out.
First off you do not have to have every page linked off the homepage as
long as you have a link to a sitemap.xml file on the homepage google will
be able to crawl all the pages as it works as a directory system for the
bots.
Secondly you can have text in an image as long as you go the correct meta
descriptions everything will be perfectly fine.
But apart from that everything else is fine.
Source - i work as an SEO manager﻿

You may be able to answer my question too!
Quick question 'avoid text in images' I plan a website redesign in October
for a travel blog. I like the blogs which have large images with the
continent name / country name in an imagine and then reader clicks the
image to reveal a country profile (bit of blurb then all their blog links
for that country). Is this the kind of thing you suggest to avoid? Cheers

+ if you want to add content through javascript to your webpage, like
loading html inside an element etc (AJAX),
google will not recognize the added content, because it cant run js.
If you really want to use it and make google understand you check this
https://developers.google.com/webmasters/ajax-crawling/docs/learn-more﻿

Finding your tutorials really useful, thank you. Hit a wall with MUV so
working on SEO. Quick question 'avoid text in images' I plan a website
redesign in October for a travel blog. I like the blogs which have large
images with the continent name / country name in an imagine and then reader
clicks the image to reveal a country profile (bit of blurb then all their
blog links for that country). Is this the kind of thing you suggest to
avoid? Cheers﻿